Solar panels in Britain: what solar panels, solar panel installation, solar panel installers and solar panel cost questions really come down to, what solar panel installations leave on a roof, what solar panels UK buyers should ask before a survey, what installing solar panels on roof coverings involves, what solar panels on a roof are warranted for, what are solar panels worth once export is counted, and what solar panel companies should evidence before anybody signs

How solar panels works

1. Start from your own consumption, not the roof. Pull twelve months of electricity use and look at when it happens. Generation you use replaces electricity at your import rate; generation you export earns a fraction of that. The point where extra panels stop replacing bought units is where an honest array stops, and it is the calculation most sales sizing skips.
2. Have the roof looked at before the array is designed. An array is a twenty five year asset. If the covering has under ten years left, the right sequence is re roof and install together rather than fixing panels to something that has to come off. A roofer can give you the remaining life in an afternoon, and it is the cheapest information in the project.
3. Get three surveyed quotes and normalise them. Put all three on one sheet: system size in kilowatts peak, modelled annual generation with its assumptions, the self consumption fraction assumed, scaffolding and making good in or out, and warranty lengths for panels, inverter and workmanship as three separate columns. Most of the apparent price gap disappears at that point.
4. Check the company, not just the price. Certification and its scope seen as a document, filed accounts at Companies House, three local references on the same roof covering, and a straight answer to who physically fits it and who attends a fault in year six. A twenty five year warranty is only as good as the company behind it.

Insurance and paperwork

Common questions

How much do solar panels cost to install in the UK?

There is no single figure, because access, roof covering and condition, the cable route to the consumer unit and the state of the board move the price more than the panels do. Get three surveyed quotes rather than a desktop estimate, and compare them on modelled generation rather than headline price.

Do I need planning permission?

Usually not for roof mounted panels on an ordinary house, because they are generally permitted development within limits. Listed buildings, conservation areas, flats and ground mounted arrays are the common exceptions, and the rules differ between England, Scotland, Wales and Northern Ireland.

Is a battery worth adding?

It raises the share of your own generation you use, which is worth money when import rates are well above export rates. Whether that covers its cost depends on its price, its usable capacity and how much you were exporting without it, so ask for both cases to be modelled.

Does the installer have to be certified?

For export payments and most funding routes, yes. Ask to see the certificate and its scope rather than a logo, and check it against the scheme's own installer search.

What is the most common mistake?

Fixing a twenty five year array to a roof covering with a few years left, and accepting a payback figure whose self consumption assumption is never stated.

Registered contractors by region

• Registered roofers in the East Midlands postcode area
• Registered roofers in the East of England postcode area
• Registered roofers in the London postcode area
• Registered roofers in the North East postcode area
• Registered roofers in the North West postcode area
• Registered roofers in the Scotland postcode area
• Registered roofers in the South East postcode area
• Registered roofers in the South West postcode area
• Registered roofers in the Wales postcode area
• Registered roofers in the West Midlands postcode area
• Registered roofers in the Yorkshire and The Humber postcode area